Transcript Potential Energy - McMaster Physics and Astronomy

TEST – Thursday at 7pm
• The test will cover things we have done in class up to
Lecture 9 (Chapter 1,2,4,5.1-5.4, 5.6, 6.1-6.3 and 8)
• Momentum will NOT be on the test
• Please look over old test (available online)
• Make sure you’re up on your reading !
• Review error calculations (done in lab)
• Look over CAPA problems (the easier ones!)
• This test is worth 15% of your mark
• There are 15 multiple choice questions on the test
Physics 1D03 - Lecture 25
TEST
Bring:
- your student card
- your calculator
- pen or pencil
- please wait for TAs to let you in the room
- if you’re not sure about a question – ASK !!!
- remain quite near the end – other will still be writing!
- do easier questions first, then go back
Physics 1D03 - Lecture 25
• Kinematics: average velocity, acceleration, vectors,
displacement, d=vt+1/2at2, v=vo+at, v22=v12+2ad,
projectile motion
• Dynamics: Free-body diagrams, forces ΣF=ma,
friction, ramp and pulleys, vectors
Physics 1D03 - Lecture 25
Graphs of x(t), v(t), a(t)
x
t
v
t
a
t
Physics 1D03 - Lecture 25
Projectile Motion
• A plane if flying horizontally at 40m/s when it drops a
package. If the package lands 181m ahead of the
point above which it was dropped, when was it
dropped and from what height ?
dv
dh
Physics 1D03 - Lecture 25
Friction
• You are pushing a 100kg fridge over a floor with
μs=0.5 and μk=0.3 with a force of 290N. What is the
magnitude of the frictional force between the fridge
and the floor.
Physics 1D03 - Lecture 25
Another look at tension
• Two blocks are being pulled on a frictionless surface
by a force Fa to the left. The mass of the first block is
m and the one behind 5m. What is the tension
between the blocks?
Fa
5m
m
Physics 1D03 - Lecture 25
Contact Force
• Two blocks, one of mass m1 and the other of mass
m2 are being pushed by a force F on a frictionless
surface.
Determine their acceleration and the magnitude of
the contact force.
m2
m1
F
Physics 1D03 - Lecture 25
Tension
• A mass m=20.4kg is suspended by two ropes as
show in the diagram below. θ1=60 and θ2=45.
Determine the tension in the strings.
θ1
θ2
Physics 1D03 - Lecture 25
Inclines
• Find a.
Physics 1D03 - Lecture 25
Pulleys
Consider the more elaborate Atwood’s
machine shown.
Assuming the rope and pulleys are
ideal, the relation between the
accelerations will be:
a1
a ) a1  a2
b ) a1  2 a2
c ) a1 
1
2
m1
a2
m2
a2
d ) The ratio
a1
depends on the values of m1 and m2
a2
Physics 1D03 - Lecture 25
More question to be added later…
(I had to go home)
Physics 1D03 - Lecture 25